Grass growth trends across GB have continued to increase this week, averaging 74.6kg DM/ha/day. In comparison to the same period last year grass growth averaged only 52.3kg DM/ha/day and 63kg DM/ha/day for the 6-year average. All regions have seen an increase in grass growth rates with the East Midlands seeing the greatest increase of 59 to 79kg DM/ha/day. With continued rainfall expected and mild conditions conducive of growth, rates of growth may remain constant.
Milk Yield from Grazing (MYFG)
Predicted MYFG has fallen this week to M+8.5 litres/day, potential DMI remained the same yet ME has dropped from 12.1 to 11.6 MJ/kg DM. to date, the season has seen reduced MYFG figures versus 2021, thanks to lower ME levels where grass has been mature from prolonged growth over winter.
What is happening with increased butterfats this season?
With increased protein levels being recorded so far, this grazing season and typically lower than average rapidly fermentable carbohydrates (RFC), the resulting trend has been a high fibre index and low acid load. This is in direct contrast to what is normally seen with spring grazing, where a high acid load and low fibre index is typically seen. While rumen conditions may be improved and the risk of butterfat depression is reduced, lower MYFG is likely due to energy use shifted towards deamination of protein and a more lignified forage with less available energy.
Pre-Cut NDF Tracker
Average NDF for the second half of this week has increased slightly to 45.2% DM, which is much higher than the average NDF level reported at the same period in 2021 of 35.9% DM. NDF this week has also remained above the target of 38 – 40% DM, similar to previous weeks, indicating many fields are ready to cut. A large range in NDF levels from 33.7 – 60.3% DM was reported this week, further highlighting the need for individual farms to analyse their grass to understand when to cut for optimal silage quality. Regionally the lowest average NDF levels were seen in the Northeast at 42.9% DM which is just above the target level. While the highest average NDF levels were seen in the Northwest and Wales and West at 45.9% DM.